A Comparison Between Rhino Cycles Renders

Rendering
1

Hello everyone,

I came across this “problem” (I am not sure if it is a problem, but it is somewhat discouraging at times). I find the Rhino cycles rendering going slower and slower.

For my comparison rendering I made a simple sphere and a metal material with 85% polishing.

In R9 WIP (as of 1.2.2026) it takes 14 seconds to complete 20 samples,
In R8 it takes 12 seconds to complete 20 samples,
In R7 it takes 9 seconds to complete 20 samples,
In R6 it takes 2 seconds to complete 20 samples.

I add the files and Systeminfo text of the R9 and R6 for comparison. Do you think this slow rendering speed is a problem with my PC only or does anybody else experience that also? Is there a fix? (At some trials at work the R9 just crashed when rendering).

Have a nice weekend!

R6 - Rendering.3dm (296.6 KB)

R9 - System Info.txt (2.8 KB)

R9 - Rendering.3dm (2.8 MB)

R6 - System Info.txt (2.6 KB)

2

Hi @Erdem

I don’t know for sure but maybe the time increase is because cycles does more/has more rendering options in the latter versions that don’t exist in the previous versions and thus the added time.

Hopefully Nathan will chime in though he’s leaving McNeel at the end of this month.

RM

3

i doubt that. the rendering engine was switched to cycles in Rhino 6 other than screwing up bump in v8 not much has changed from then on i believe. if anything, above 7 it should be much faster since the engine was switched from cycles to cycles x in v8.

4

Yeah man, I don’t understand why. I will now update my GPU driver to the latest update and see if that changes anything.

5

Updated the driver, now it is down to 10 seconds… Still a lot slower than R6. It is just a simple scene. Why is this so?

Here is the new System Info:

Rhino 9 SR0 2026-1-27 (Rhino WIP, 9.0.26027.12305, Git hash:master @ 5f15e63747872f59c771ecf3d824aa18e045777a)
License type: Educational, build 2026-01-27
License details: Cloud Zoo
Expires on: 2026-03-13

Windows 11 (10.0.26200 SR0.0) or greater (Physical RAM: 16GB)
.NET 9.0.1

Computer platform: LAPTOP - Plugged in [100% battery remaining]

Non-hybrid graphics configuration using DirectX
Primary display: NVIDIA GeForce RTX 3070 Laptop GPU (NVidia) Memory: 8GB, Driver date: 1-20-2026 (M-D-Y). DirectX(11)

Integrated accelerated graphics device with 4 adapter port(s)

  • Windows Main Display is laptop’s integrated screen or built-in port

Secondary graphics devices.
Intel(R) UHD Graphics (Intel) Memory: 1GB, Driver date: 12-12-2022 (M-D-Y).

Integrated graphics device with 4 adapter port(s)

  • Secondary monitor is laptop’s integrated screen or built-in port
    Intel(R) UHD Graphics (Intel) Memory: 1GB, Driver date: 12-12-2022 (M-D-Y).

Integrated graphics device with 4 adapter port(s)

  • Secondary monitor is laptop’s integrated screen or built-in port
    Intel(R) UHD Graphics (Intel) Memory: 1GB, Driver date: 12-12-2022 (M-D-Y).

Integrated graphics device with 4 adapter port(s)

  • Secondary monitor is laptop’s integrated screen or built-in port

DirectX Settings
Safe mode: Off

OpenBLAS: OpenBLAS 0.3.30 DYNAMIC_ARCH NO_AFFINITY Haswell MAX_THREADS=64.

Rhino plugins that do not ship with Rhino
C:\Program Files\Common Files\McNeel\Rhinoceros\7.0\Plug-ins\CodeListener (8c4235b6-64bc-4508-9166-bef8aa151085)\0.1.7.0\Rhino 5.0\x64\CodeListener.rhp “CodeListener” 0.1.7.0
D:\DEPO\PROGRAM DEPO\3D\Rhinoceros\Plugins\RPTool - R6 R7\rptool.rhp “Rhino.NET SDK” 0.0.0.0
C:\ProgramData\McNeel\Rhinoceros\7.0\Plug-ins\Datasmith Rhino Exporter (d1fdc795-b334-4933-b680-088119cdc6bb)\DatasmithRhino7.rhp “Datasmith Exporter” 5.0.3.0

Rhino plugins that ship with Rhino
C:\Program Files\Rhino 9 WIP\Plug-ins\Commands.rhp “Commands” 9.0.26027.12305
C:\Program Files\Rhino 9 WIP\Plug-ins\rdk.rhp “Renderer Development Kit”
C:\Program Files\Rhino 9 WIP\Plug-ins\UpdatesAndStatistics\UpdatesAndStatistics.rhp “UpdatesAndStatistics” 9.0.26027.12305
C:\Program Files\Rhino 9 WIP\Plug-ins\RhinoRenderCycles.rhp “Rhino Render” 9.0.26027.12305
C:\Program Files\Rhino 9 WIP\Plug-ins\rdk_etoui.rhp “RDK_EtoUI” 9.0.26027.12305
C:\Program Files\Rhino 9 WIP\Plug-ins\NamedSnapshots.rhp “Snapshots”
C:\Program Files\Rhino 9 WIP\Plug-ins\MeshCommands.rhp “MeshCommands” 9.0.26027.12305
C:\Program Files\Rhino 9 WIP\Plug-ins\SectionTools.rhp “SectionTools”
C:\Program Files\Rhino 9 WIP\Plug-ins\RhinoCycles.rhp “RhinoCycles” 9.0.26027.12305
C:\Program Files\Rhino 9 WIP\Plug-ins\3dxrhino.rhp “3Dconnexion 3D Mouse”
C:\Program Files\Rhino 9 WIP\Plug-ins\Displacement.rhp “Displacement”

6

20 samples may not be enough for a meaningful comparison. Try 1000 (here R6 completed in 17 seconds, R9 in 16 seconds).

Look at your images - one is zoomed in more than the other. For a trustworthy comparison you need them to be the same. Why not just run with the R6 image in both environments? You also need to ensure that the viewports are the same pixel sizes.

The environments used in the two renders have different levels of detail. For comparison purposes they should be the same.

7

R6 - ss
R6 - ss1920×1015 214 KB

R6 Render

R9 - ss
R9 - ss1920×1032 196 KB

R9 Render

Okay, there is a huge difference in the rendering quality. But still it seems like a lot of speed difference.

On R6 14 seconds for 100 samples and
on R9 1:14.

That’s a huge difference. Idk, maybe it is time for a PC update.

8

R9 has a new, much newer Cycles version in it, just recently changed, and it’s probably not really time yet to worry about comparisons like this.